A New Biomarker for Resolving Central Serous Chorioretinopathy
In the evolving landscape of multimodal imaging for central serous chorioretinopathy (CSCR), we are constantly identifying new biomarkers that help refine our understanding of disease activity and prognosis. While features like the “double-layer sign” (DLS) or RPE apertures are well-established, a recent multicenter study published in RETINA has introduced a novel finding: the “scolex” sign.
What is the Scolex Sign?
The “scolex” sign is a discrete, well-defined hyperreflective focus or dot located on the inner wall of a serous pigment epithelial detachment (PED). The term is derived from its morphological resemblance on OCT to the scolex (head) of a parasitic cyst within a cystic space.
This feature was identified in approximately 18% of eyes with large serous PEDs (defined as >100 μm in height). Interestingly, while the sign is distinctly visible on OCT B-scans and as a hyperreflective spot on infrared (IR) imaging, it typically has no visible correlate on fluorescein angiography or blue autofluorescence.
Key Clinical Characteristics
According to the MiCRON Study Group’s retrospective analysis of 291 eyes, several clinical trends distinguish eyes exhibiting this sign:
- Anatomical Location: PEDs with the “scolex” sign are more likely to be centrally located and are significantly closer to the foveal center compared to those without the sign.
- Disease Phase: The presence of the sign appears to be associated with a resolving stage of the disease. In fact, some eyes that lacked the sign at baseline developed it as their subretinal fluid (SRF) resolved.
- Higher Resolution Rates: Eyes with the “scolex” sign demonstrated a significantly higher rate of spontaneous PED flattening and a trend toward more frequent SRF resolution compared to age-matched controls.
Pathophysiology: A Reparative Marker?
The exact nature of the hyperreflective focus remains speculative without histopathological confirmation, but researchers suggest it represents localized reparative changes. Hypotheses include:
- Pigment clumping or fibrin deposits acting as a “seal” for an RPE microrip.
- A collection of inflammatory cells responding to a localized RPE injury.
Essentially, the “scolex” may be the structural evidence of the eye’s defense mechanism attempting to close a leak point and restore RPE integrity.
Clinical Takeaways for the Retina Specialist
For the busy clinician, the “scolex” sign should be viewed as a benign imaging feature. It does not correlate with poorer visual outcomes, nor does it increase the immediate risk of developing choroidal neovascularization (CNV).
While its presence might not necessitate a change in acute management, recognizing the scolex sign can provide reassurance that the eye may be entering a reparative or resolving phase. It serves as another valuable tool in our multimodal imaging toolkit for monitoring the natural history and treatment response of CSCR.
Reference: Hasan N, Zarnegar A, Sadeghi E, et al. The “Scolex” Sign: A Distinct Hyperreflective Foci on the Wall of Serous Pigment Epithelial Detachments in Central Serous Chorioretinopathy – Micron Report Number Seven. RETINA. 2026;46(5):871–880.
